Multi-user Operating Systems

Introduction

Since only one user may interact with the computer at any given time, the operating system we use on our personal computers, laptops, tablets, and phones is sometimes referred to as a single-user operating system.

A Multi-user Operating System is what?

An operating system that enables numerous users to connect and utilize a single operating system is known as a multi-user operating system. Users communicate with it through terminals, computers, or other devices like printers that provide them network access. To prevent problems with one user from affecting other users in the chain, the operating system should have to balance the needs of all of its users.

An operating system is a piece of software that serves as an interface for users and computer hardware, managing things like memory, files, and processors, among other things. To prevent problems with one user from affecting other users in the chain, the operating system should have to balance the needs of all its users.

Multiple users can simultaneously access different computer resources when the operating system is multi-user. A network of different personal computers connected to a mainframe computer system is used to offer access. A multi-user operating system enables simultaneous access to a single machine by numerous users. The mainframe computer system can receive and deliver information from many personal PCs. As a result, additional personal computers are clients to the mainframe computer's server.

The multi-user operating system's components are:

Main memory makes up memory (RAM). The operating system's main memory is crucial since it limits the number of concurrently running apps.

1. Memory: The various kinds of physical storage on a hard drive. How many applications may be executed simultaneously depends on the hard drive, which can store significant data. Diskette, floppy Although more affordable, it is still potable.
2. Kernel: This part is included in the computer system's main memory and has direct hardware communication capabilities. The multi-user operating system uses the kernel component at a low level and is written in a low-level language.
3. Processor: The central processor unit (CPU) is the computer's brain (CPU).
4. Device handler: The main objective of the device handler is to fulfill all requests from the device request queue. The I/O request block from the queue side is the first thing the device handler discards while operating in continuous cycle mode. The handler is based on the idea of a queue where the first in, first out (FIFO) rule is followed.
5. Spooler: Line-based simultaneous peripheral output. The spooler conducts all computer operations simultaneously, which also outputs the results.
6. The user interface, or UI: Make the environment everyone uses to access the computer system easy. One of the systems that use multi-user programming techniques is the Mainframe. Banks frequently use it to hold information about transactions and bank accounts. Security and scalability are two ways why the Mainframe is beneficial.

Operating systems for many users can be classified as one of the following:

1. Distributed System
2. Time-slicing technology
3. A system with many processors

Decentralized system:

A collection of several computers situated on various machines makes up the distributed operating system, commonly referred to as distributed computing. Each system represents a single, cohesive system to the user. The network will facilitate communication between them and the end user. This method is set up so several requests may be addressed simultaneously, ultimately fulfilling each request.

1. A distributed operating system, sometimes referred to as distributed computing, is a group of components present on several computers that communicate, coordinate, and seem to the user as a single cohesive system. The end user will use the network to connect with or control them.
2. This system allocates resources so that several requests may be addressed at once, ultimately allowing for the fulfillment of each request.
3. Users may do various transactions utilizing a single network while sitting at home.

Examples include mobile applications and online banking.

Time-slicing method:

Every user speaking in this system is given a brief period of CPU time. Each assignment is given a short amount of time. Each CPU slice is allotted one time, broken into smaller time chunks. The schedule determines whether to execute the following section of the job. This schedule carries out the run instructions that must be carried out. The operating system will handle the user's request among the connected users if the user chooses to take turns. The single-user operating system cannot use this capability. They both use the mainframe system at the same time.

It is a system in which a little CPU time is allotted to each user’s job. In other words, each work is given a little window of time. The user's eyes see these time slices as being too tiny. A system component known as the "Scheduler" internally decides whether to execute the subsequent work. Depending on the priority cycle, this scheduler determines and executes the run instruction or job that must be performed. Because the users can switch off, the operating system will divide user requests among the connected users. In the Single User Operating System, where the user and the computer interact directly, this capability is not accessible.

A user will be given a set time slice to complete a difficult job in the time-sliced system's Mainframe, which is used as an example in practical exams.

An example of a time-sliced system is the Mainframe.

Multi-processor systems

A multi-processor system uses several processors simultaneously. Improve the performance as a whole. If one processor malfunctions, the others keep running. Spreadsheets and music players are two examples of multi-processor systems which employ many processors concurrently. The job would be finished considerably quicker than with the single-user operating system since all the processors would execute concurrently.

Word processors, spreadsheets, music players, etc., may all be opened simultaneously on the Windows operating system without compromising the performance of any of the open applications. This is an example of a multi-processing system in action.

Features

These are some of the features of the multi-user operating system:

1. Resource sharing: This corresponds to time slicing and allows users to share various peripherals, such as printers, with various files or data.
2. Background sharing and time sharing
3. Invisibility: The user is unaware of many features in multi-user operating systems.
4. Numerous processing: As previously said, we can run multiple applications simultaneously. For example, students might update a word document while searching the internet (perhaps on Google) and attach an excel file immediately.
5. Resource sharing: This function can be compared to time slicing. We may share various peripherals, including printers, hard discs, and other devices, or even exchange various files or data. The webmail system is one such example that may be used in this context. This shows that the OS can accommodate millions of users concurrently when thousands of people log on at once to check their emails, send messages, etc. Therefore, a webmail program needs thousands of computers, each of which can serve thousands of users simultaneously.
6. Data processing in the back end: Other applications can communicate with the processor in the front end simultaneously thanks to this feature, which enables data processing at the rear end when it isn't permitted to process it there. The multi-user operating system has several functionalities that are unseen to users. This is due to factors like how instinctively the OS operates or how lower-level events like formatting the disc and other things happen.

Multi-User Operating System Working Mode

The Master system should be the core of any multi-operating system.

All users have access to this Master system at all times and from anywhere and may open their own working views of the system. The "Local perspective" is what we refer to as. This is the multi-user operating system's operational model.

Users may add, remove, and edit records by their needs. Unless a user shares it or saves it to the Master System, this working model won't be available to the other users of the system.

Multi-User Operating System Components:

The CPU (Central Processing Unit), sometimes known as the computer's brain, is one of three components that comprise the multi-user operating system. Large machines would demand more ICS for the CPU. On smaller devices, however, the CPU is mapped onto a single chip known as the microprocessor.

1. Memory: The computer's internal physical memory is where storing takes place. Every program performed must be transferred from a physical storage, such as a hard drive, since the system can rectify data already existing in the main memory. Because it controls how many applications may run at once and how much data is available, main memory is always seen as crucial. The many kinds of physical storage may be divided into:
2. Hard discs: They can store a lot of data and control how many applications may be executed simultaneously. Lasers are used to read and write data on optical drives. However, unlike portable hard drives, they cannot store vast amounts of data. Writing and reading files are done on a CD (Compact Disk).
3. Tapes: They are also reasonably priced. Although they have a lot of memory, random data access is impossible.
4. Terminals:
   1. Dumb Terminal: It comes equipped with a computer and a keyboard but lacks processing capability.
   2. They are utilized for mainframe system remote work.
   3. Smart Terminals: You may use a smart terminal to perform basic editing and processing. They lack physical storage components like hard discs yet are nonetheless reasonably priced. It consists of four software parts:
      • Kernel: The kernel is referred to as the computer system's low-level component. Any blocks on the input/output device are likewise discarded as it operates continually.
      • Spooler: Spooler is mostly used in output devices like printers, and it runs all active tasks on the computer while producing the proper output.
      • Devices for input and output: These are used to send and receive data.
      • User interface (UI): UI is the point of contact between users and software/hardware, providing a simple working environment for all users and acting as a mysterious element in multi-user operating systems.
        1. Let's examine one specific example utilized extensively throughout the world.
        2. One system that utilizes the idea of a multi-user operating system is the Mainframe. Banks commonly use it to hold information about transactions and bank accounts.

Benefits:

1. It facilitates the exchange of data and information between users and the sharing of physical resources like printers.
2. It prevents interruption since if one computer on the network fails, it won't impact the other computers connected.
3. Users can distribute their works among themselves.
4. Data backup is possible with the multi-user operating system, and its services are dependable and organized. The multi-user operating system is highly beneficial for improving the economy.

Drawbacks

1. The disadvantages of setting up a mainframe computer include the need for pricey hardware.
2. The system's overall performance is decreased when numerous people log on or utilize the same system.